The present invention relates to thread cutting apparatus and more particularly to tools adapted to recondition male threads.
The lug studs for receiving vehicle wheels are often subjected to damage by placement and removal of the wheels, by rocks, rust and inadvertent cross threading. It is often desirable to renew or recondition the threads of the studs rather than simply replace the studs by removing them from the wheel drum. The replacement procedure is relatively complex since the drum must be removed from the axle to allow removal and replacement of the worn studs. Provision of a tool that would enable one to recondition the studs without removing them from the wheel drum is therefore desirable.
U.S. Pat. No. 2,822,555 to Davis shows an elongated tool with thread members that are assemblable about a bolt shank. The members are engaged by a screw and selectively tightened about the stud shank before the tool is operated to turn about the shank axis to recondition the threads on the shank.
U.S. Pat. Nos. 2,700,166 and 2,718,646 show reconditioning tools having die members that are closed by cam surfaces in response to rotational movement of the tool in a particular direction. The die members loosely ride over the threads on the shank to be reconditioned as the tool is being positioned adjacent the shank base. Then, when the tool is turned in an opposite direction, cams force teeth cutting serrations into the existing teeth to recondition the teeth as the tool is turned or backed off the shank.
U.S. Pat. No. 2,557,609 is simply illustrative of a hub nut of a particular configuration adapted to rethread and peen a lug stud.
The present apparatus utilizes an expandable and retractable chuck that includes thread cutting serrations that separate and contract in response to pivotal movement of the tool handle. The thread cutting serrations may be placed loosely over damaged lug studs to position the serrations adjacent the base of the stud. The handle is them pivoted on the tube to contract the teeth cutting serrations about the stud shank. Rethreading is then accomplished as the handle is operated to turn the tool about the lug stud axis. The device is further adapted to receive collet chucks adapted to accommodate lug studs of different size and/or thread configuration.